Improved Target Volume Definition for Radiotherapeutic Management of Parotid Gland Cancers by use of Multimodality Imaging: An Original Article
Selcuk Demiral*, Omer Sager, Ferrat Dincoglan and Murat Beyzadeoglu
Department of Radiation Oncology; University of Health Sciences, Gulhane Medical Faculty, Ankara, Turkey
Submission: April 28, 2022; Published: May 10, 2022
*Corresponding Address: Selcuk Demiral, University of Health Sciences, Gulhane Medical Faculty, Department of Radiation Oncology, Gn.Tevfik Saglam Cad. 06018, Etlik, Kecioren, Ankara, Turkey
How to cite this article: Selcuk D, Omer S, Ferrat D, Murat B. Improved Target Volume Definition for Radiotherapeutic Management of Parotid Gland Cancers by use of Multimodality Imaging: An Original Article. Canc Therapy & Oncol Int J. 2022; 21(3): 556062. DOI:10.19080/CTOIJ.2022.21.556062
Abstract
Objective: Parotid gland cancers account for the majority of salivary gland malignancies. In terms of management, surgical resection is a principal treatment modality. Total parotidectomy is a widely accepted surgical procedure, however, there may be the risk for facial nerve palsy. Radiation therapy (RT) has a well-established role for management of parotid gland cancers. RT may serve as a treatment modality for definitive management in the setting of inoperability. Also, RT may have an integral role as part of multidisciplinary management or as salvage therapy for recurrent disease. Clinical target volume definition is a critical part of radiotherapeutic management, and should be performed vigilantly to achieve optimal treatment results. Herein, we evaluate target volume definition for radiotherapeutic management of parotid gland cancers by use of multimodality imaging.
Materials and methods: Either the CT-simulation images only or registered CT and MR images were utilized for target volume determination of patients with parotid gland cancers who were referred for RT at Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences. A comparative analysis has been performed to assess target definition by CT only and with incorporation of CT-MR registration based imaging.
Results: Patients referred to Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences for radiotherapeutic management of parotid gland cancers were assessed for target volume definition by CT-only imaging or CT-MR registration based imaging in this study. Ground truth target volume was found to be identical with CT-MR registration based imaging in this study for radiotherapeutic management of parotid gland cancers.
Conclusion: This study reveals improved treatment volume determination for parotid gland cancers by incorporating of MRI in the RT treatment planning procedure despite the need for further supporting evidence.
Keywords: Parotid gland cancer; Radiation therapy (RT); Magnetic resonance imaging (MRI)
Introduction
Salivary gland neoplasms are relatively rare tumors of the head and neck region, however, they include a great variety of histological types which renders them a formidable challenge for imaging specialists and clinicians. There is a wide range of differential diagnoses which may effect both prognosis and management strategies. Patients with salivary gland neoplasms may suffer from a variety of symptoms based on lesion size, localization, and association with critical structures. The head and neck region composes a relatively smaller part of the human body, nevertheless, it includes very important parts associated with critical functions. Within this context, optimal management of tumors located in this critical body region is mandatory to avoid functional impairments along with quality of life deterioration.
Imaging may have a major role for assessment of salivary gland neoplasms [1-5]. Differentiation between benign and malign tumors may be challenging, however, imaging characteristics may assist in resolving this critical issue. Preoperative localization of the lesions may be detected by imaging. Also, imaging may allow for characterization of the tumors along with documentation of locoregional extension, perineural spread, and nodal involvement. Another utility of imaging is for differential diagnosis, detecting recurrent disease, assesseing treatment response, and predicting malign transformations.
Parotid gland cancers account for the majority of salivary gland malignancies. In terms of management, surgical resection is a principal treatment modality [6-10]. Total parotidectomy is a widely accepted surgical procedure, however, there may be the risk for facial nerve palsy. Radiation therapy (RT) has a wellestablished role for management of parotid gland cancers [11-18]. RT may serve as a treatment modality for definitive management in the setting of inoperability. Also, RT may have an integral role as part of multidisciplinary management or as salvage therapy for recurrent disease. Adjuvant RT in the postoperative setting may be utilized for T3 or T4 tumors, bone invasion, incomplete or close resection margins, and pathological lymph node positivity.
Clinical target volume definition is a critical part of radiotherapeutic management, and should be performed vigilantly to achieve optimal treatment results [19]. It is very important to improve target definition for radiotherapeutic management of parotid gland cancers in the era of sophisticated RT techniques including Intensity Modulated Radiation Therapy (IMRT), Image Guided Radiation Therapy (IGRT), Adaptive Radiation Therapy (ART). Robust immobilization techniques, multimodality imaging and image fusion methods have clearly contributed to achieving optimized radiotherapeutic results. While current RT practice mostly utilizes Computed Tomography (CT) imaging for treatment simulation, additional information from other imaging modalities may assist in improved delineation of target volumes and critical structures. Herein, we evaluate target volume definition for radiotherapeutic management of parotid gland cancers by use of multimodality imaging.
Materials and Methods
A comparative analysis has been performed in this study to investigate whether multimodality imaging may improve target volume definition along with interobserver and intraobserver variations for radiotherapeutic management of parotid gland cancers. For this purpose, we comparatively evaluated RT target volume determination by integrating Magnetic Resonance Imaging (MRI) or by CT-simulation images only. For actual treatment and comparison purposes, a ground truth target volume was defined for each patient on a collaborative basis by board certified radiation oncologists after detailed assessment, colleague peer review, and consensus. Referred patients had parotid gland cancers, and treatment with RT was decided after thorough multidisciplinary evaluation on an individual basis. Appropriate treatment strategies and protocols were considered by taking into account patient, tumor, and treatment characteristics.
Lesion sizes, localizations and association with normal tissues, expected outcomes of management, patient symptomatology and preferences along with logistical issues were discussed before the decision making process.
RT has been delivered by Synergy (Elekta, UK) linear accelerator (LINAC) available at our tertiary referral institution. CT-simulation was performed for all patients at CT-simulator (GE Lightspeed RT, GE Healthcare, Chalfont St. Giles, UK) in order to acquire high quality treatment planning images. After CT-simulation has been completed, acquired treatment planning images have been transferred to the contouring workstation (SimMD, GE, UK) by use of the network. Structure sets including treatment volumes and critical structures were defined. Either the CT-simulation images only or registered CT and MR images were utilized for target volume determination. A comparative analysis has been performed to assess target definition by CT only and with incorporation of CT-MR registration based imaging.
Results
Patients referred to Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences for radiotherapeutic management of parotid gland cancers were assessed for target volume definition by CT-only imaging or CTMR registration based imaging in this study. Assessed tumor related parameters included the T staging, bony invasion, status of resection margins in the setting of surgery, and pathological lymph node positivity and other characteristics. Also, patient age, symptomatology, performance status, lesion location and association with critical structures were considered. We made use of reports by American Association of Physicists in Medicine (AAPM) and International Commission on Radiation Units and Measurements (ICRU) in RT treatment planning. In light of current guidelines and clinical experience, radiation physicists have generated plans with consideration of relevant critical organ dose constraints. Tissue heterogeneity. electron density, CT number and HU values in CT images were among the considered parameters by the radiation physicist in RT treatment planning. A pertinent aspect of treatment planning included achieving optimal treatment volume coverage without violation of critical organ dose constraints. The determination of ground truth target volume was done by board certified radiation oncologists following detailed assessment, colleague peer review, and consensus. Ground truth target volume was utilized for actual treatment and for comparison purposes. Treatment delivery was accomplished by incorporation of IGRT techniques such as kilovoltage cone beam CT and electronic digital portal imaging. Ground truth target volume was found to be identical with CTMR registration based imaging in this study for radiotherapeutic management of parotid gland cancers.
Discussion
Although salivary gland neoplasms account for a relatively smaller proportion of head and neck cancers, they include a variety of histological types. Imaging specialists and clinicians may have difficulties in diagnosis, and there may be a wide range of differential diagnoses. Patient symptomatology may vary with regard to lesion size, localization, and association with critical structures. The head and neck region is a relatively smaller portion of the human body, however, this critical region includes very important parts which are associated with critical body functions. Thus, it is imperative to consider adverse effects of therapies to get rid of functional impairments and quality of life deterioration.
Imaging techniques play an essential role in evaluation of salivary gland neoplasms [1-5]. It may be typically challenging to differentiate between benign and malign tumors, nevertheless, certain imaging characteristics may aid in differentiation. Preoperative tumor localization may be detected by imaging modalities. Imaging may also allow for tumoral characterization and documentation of critical characteristics including locoregional extension, perineural spread, and nodal involvement. Differential diagnosis, detection of recurrent disease, treatment response evaluation, and prediction of malign transformations may also be facilitated by use of imaging techniques.
Parotid gland cancers constitute the majority of salivary gland malignancies. Surgery is a main therapeutic modality [6- 10]. A very common procedure for surgical resection is total parotidectomy, nevertheless, there may be the risk for facial nerve palsy. RT plays a significant role for management of parotid gland cancers [11-18]. RT may be used for definitive management in the setting of inoperability, and also may play a critical role as part of multidisciplinary management or as salvage therapy for recurrent disease. Indications for adjuvant RT in the postoperative setting may include T3 or T4 tumors, bone invasion, incomplete or close resection margins, and pathological lymph node positivity. Definition of the clinical target volume may be a complex procedure, and should be performed carefully for optimal radiotherapeutic management [19]. Multimodality imaging technologies and image fusion methods have improved target definition for several cancers. There is accumulating data supporting the utility of multimodality imaging for target definition of many tumors [20- 52]. In the current RT practice, most commonly utilized imaging modality for treatment simulation purposes includes the CT. However, MRI may offer additional advantages over CT and may aid in improved target definition. In our study, ground truth target volume was found to be identical with CT-MR registration based imaging for radiotherapeutic management of parotid gland cancers. Our study may add to the growing body of evidence suggesting improved target volume determination by use of multimodality imaging.
There have been many advances in the context of radiation oncology recently with introduction of molecular imaging methods, automatic segmentation techniques, stereotactic RT, IMRT, IGRT, and ART [53-90]. In light of these advances, precision and accuracy in target volume definition has gained utmost importance. Within this context, our study may have clinical implications for routine incorporation of multimodality imaging in radiotherapeutic management of parotid gland cancers.
In conclusion, this study reveals improved treatment volume determination for parotid gland cancers by incorporating of MRI in the RT treatment planning procedure despite the need for further supporting evidence.
Conflict of Interest
There are no conflicts of interest and no acknowledgements.
References
- Thoeny HC (2007) Imaging of salivary gland tumours. Cancer Imaging 7(1): 52-62.
- Hiyama T, Kuno H, Sekiya K, Oda S, Kobayashi T (2021) Imaging of Malignant Minor Salivary Gland Tumors of the Head and Neck. Radiographics 41(1): 175-191.
- Abdel Razek AAK, Mukherji SK (2018) State-of-the-Art Imaging of Salivary Gland Tumors. Neuroimaging Clin N Am 28(2): 303-317.
- Maraghelli D, Pietragalla M, Cordopatri C, Nardi C, Peired AJ, et al. (2021) Magnetic resonance imaging of salivary gland tumours: Key findings for imaging characterisation. Eur J Radiol 139: 109716.
- Christe A, Waldherr C, Hallett R, Zbaeren P, Thoeny H (2011) MR imaging of parotid tumors: typical lesion characteristics in MR imaging improve discrimination between benign and malignant disease. AJNR Am J Neuroradiol 32(7): 1202-1207.
- Cracchiolo JR, Shaha AR (2016) Parotidectomy for Parotid Cancer. Otolaryngol Clin North Am 49(2): 415-424.
- Thielker J, Wahdan A, Buentzel J, Kaftan H, Boeger D, et al. (2021) Long-Term Facial Nerve Outcome in Primary Parotid Cancer Surgery: A Population-Based Analysis. Laryngoscope 131(12): 2694-2700.
- Park YM, Kang MS, Kim DH, Koh YW, Kim SH, et al. (2020) Surgical extent and role of adjuvant radiotherapy of surgically resectable, low-grade parotid cancer. Oral Oncol 107: 104780.
- Lewis AG, Tong T, Maghami E (2016) Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland. Otolaryngol Clin North Am 49(2): 343-380.
- Shah K, Javed F, Alcock C, Shah KA, Pretorius P, et al. (2011) Parotid cancer treatment with surgery followed by radiotherapy in Oxford over 15 years. Ann R Coll Surg Engl 93(3): 218-222.
- Matthiesen C, Thompson S, Steele A, Thompson D, Ahmad S, et al. (2010) Radiotherapy in treatment of carcinoma of the parotid gland, an approach for the medically or technically inoperable patient. J Med Imaging Radiat Oncol 54(5): 490-496.
- Geiger JL, Ismaila N, Beadle B, Caudell JJ, Chau N, et al. (2021) Management of Salivary Gland Malignancy: ASCO Guideline. J Clin Oncol 39(17): 1909-1941.
- Terhaard CH, Lubsen H, Rasch CR, Levendag PC, Kaanders HH, et al. (2005) The role of radiotherapy in the treatment of malignant salivary gland tumors. Int J Radiat Oncol Biol Phys 61(1): 103-111.
- Mendizabal MR, Andueza SF, Sarda IQ, Campo M, Felipe GA, et al. (2021) Adjuvant radiotherapy in malignant tumors of parotid. Experience of the Navarra Hospital Complex. Rep Pract Oncol Radiother 26(6): 962-967.
- Terhaard CH (2007) Postoperative and primary radiotherapy for salivary gland carcinomas: indications, techniques, and results. Int J Radiat Oncol Biol Phys 69(2): S52-55.
- Thomson DJ, Slevin NJ, Mendenhall WM (2016) Indications for Salivary Gland Radiotherapy. Adv Otorhinolaryngol 78: 141-147.
- Larnaudie A, Marcy PY, Delaby N, Costes Martineau V, Troussier I, et al. (2022) Radiotherapy of salivary gland tumours. Cancer Radiother 26(1-2): 213-220.
- Harrison LB, Armstrong JG, Spiro RH, Fass DE, Strong EW (1990) Postoperative radiation therapy for major salivary gland malignancies. J Surg Oncol 45(1): 52-55.
- Armstrong K, Ward J, Hughes NM, Mihai A, Blayney A, et al. (2018) Guidelines for Clinical Target Volume Definition for Perineural Spread of Major Salivary Gland Cancers. Clin Oncol (R Coll Radiol) 30(12): 773-779.
- Beyzadeoglu M, Sager O, Demiral S, Dincoglan F (2022) Reappraisal of multimodality imaging for improved Radiation Therapy (RT) target volume determination of recurrent Oral Squamous Cell Carcinoma (OSCC): An original article. J Surg Surgical Res 8: 004-008.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2021) Radiation Therapy (RT) target determination for irradiation of bone metastases with soft tissue component: Impact of multimodality imaging. J Surg Surgical Res 7: 042-046.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2021) Evaluation of Changes in Tumor Volume Following Upfront Chemotherapy for Locally Advanced Non Small Cell Lung Cancer (NSCLC). Glob J Cancer Ther 7: 031-034.
- Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2021) Multimodality Imaging Based Treatment Volume Definition for Reirradiation of Recurrent Small Cell Lung Cancer (SCLC). Arch Can Res 9: 1-5.
- Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2021) Evaluation of Target Definition for Management of Myxoid Liposarcoma (MLS) with Neoadjuvant Radiation Therapy (RT). Biomed J Sci Tech Res 33: 26171-26174.
- Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2021) Assessment of the role of multimodality imaging for treatment volume definition of intracranial ependymal tumors: An original article. Glob J Cancer Ther 7: 043-045.
- Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2021) Assessment of Multimodality Imaging for Target Definition of Intracranial Chondrosarcomas. Canc Therapy Oncol Int J 18: 001-005.
- Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2021) Impact of Multimodality Imaging to Improve Radiation Therapy (RT) Target Volume Definition for Malignant Peripheral Nerve Sheath Tumor (MPNST). Biomed J Sci Tech Res 34: 26734-26738.
- Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2021) Radiation Therapy (RT) Target Volume Definition for Peripheral Primitive Neuroectodermal Tumor (PPNET) by Use of Multimodality Imaging: An Original Article. Biomed J Sci & Tech Res 34(4): 26970-26974.
- Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2021) Assessment of posterior fossa target definition by multimodality imaging for patients with medulloblastoma. J Surg Surgical Res 7: 037-041.
- Dincoglan F, Beyzadeoglu M, Demiral S, Sager O (2020) Assessment of Treatment Volume Definition for Irradiation of Spinal Ependymomas: an Original Article. ARC Journal of Cancer Science 6(1): 1-6.
- Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2020) Multimodality Imaging Based Target Definition of Cervical Lymph Nodes in Precise Limited Field Radiation Therapy (Lfrt) for Nodular Lymphocyte Predominant Hodgkin Lymphoma (Nlphl). ARC Journal of Cancer Science 6(2): 06-11.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Assessment of Target Volume Definition for Irradiation of Hemangiopericytomas: An Original Article. Canc Therapy & Oncol Int J 17(2): 555959.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Treatment Volume Determination for Irradiation of chordoma: an Original Article. International Journal of Research Studies in Medical and Health Sciences 5(10): 3-8.
- Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2020) Target Definition of orbital Embryonal Rhabdomyosarcoma (Rms) by Multimodality Imaging: An Original Article. ARC Journal of Cancer Science 6(2): 12-17.
- Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2020) Utility of Multimodality Imaging Based Target Volume Definition for Radiosurgery of Trigeminal Neuralgia: An Original Article. Biomed J Sci & Tech Res 26: 19728-19732.
- Demiral S, Beyzadeoglu M, Dincoglan F, Sager O (2020) Assessment of Target Volume Definition for Radiosurgery of Atypical Meningiomas with Multimodality Imaging. Journal of Hematology and Oncology Research 3: 14-21.
- Beyzadeoglu M, Dincoglan F, Sager O, Demiral S (2020) Determination of Radiosurgery Treatment Volume for Intracranial Germ Cell Tumors (GCTS). Asian Journal of Pharmacy, Nursing and Medical Sciences 8(3): 18-23.
- Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2020) Target Volume Definition for Stereotactic Radiosurgery (SRS) Of Cerebral Cavernous Malformations (CCMs). Canc Therapy & Oncol Int J 15: 555917.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Treatment Volume Determination for Irradiation of Recurrent Nasopharyngeal Carcinoma with Multimodality Imaging: An Original Article. ARC Journal of Cancer Science 6(2): 18-23.
- Demiral S, Beyzadeoglu M, Dincoglan F, Sager O (2020) Evaluation of Radiosurgery Target Volume Definition for Tectal Gliomas with Incorporation of Magnetic Resonance Imaging (MRI): An Original Article. Biomedical Journal of Scientific & Technical Research (BJSTR) 27: 20543-20547.
- Beyzadeoglu M, Dincoglan F, Demiral S, Sager O (2020) Target Volume Determination for Precise Radiation Therapy (RT) of Central Neurocytoma: An Original Article. International Journal of Research Studies in Medical and Health Sciences 5(3): 29-34.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Target Volume Determination for Irradiatıon of Pilocytic Astrocytomas: An Original Article. ARC Journal of Cancer Science 6(1): 1-5.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Radiosurgery Treatment Volume Determination for Brain Lymphomas with and without Incorporation of Multimodality Imaging. Journal of Medical Pharmaceutical and Allied Sciences 9(1): 2398-2404.
- Beyzadeoglu M, Sager O, Dincoglan F, Demiral S (2019) Evaluation of Target Definition for Stereotactic Reirradiation of Recurrent Glioblastoma. Arch Can Res 7: 3.
- Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2019) Incorporation of Multimodality Imaging in Radiosurgery Planning for Craniopharyngiomas: An Original Article. SAJ Cancer Sci 6: 103.
- Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2019) Evaluation of the Impact of Magnetic Resonance Imaging (MRI) on Gross Tumor Volume (GTV) Definition for Radiation Treatment Planning (RTP) of Inoperable High Grade Gliomas (HGGs). Concepts in Magnetic Resonance Part A 2019: 4282754.
- Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2019) Assessment of target definition based on Multimodality imaging for radiosurgical Management of glomus jugulare tumors (GJTs). Canc Therapy & Oncol Int J 15: 555909.
- Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2019) Multimodality Imaging for Radiosurgical Management of Arteriovenous Malformations. Asian Journal of Pharmacy, Nursing and Medical Sciences 7: 7-12.
- Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2019) Evaluation of Radiosurgery Target Volume Determination for Meningiomas Based on Computed Tomography (CT) And Magnetic Resonance Imaging (MRI). Cancer Sci Res Open Access 5: 1-4.
- Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2019) Utility of Magnetic Resonance Imaging (Imaging) in Target Volume Definition for Radiosurgery of Acoustic Neuromas. Int J Cancer Clin Res 6: 119.
- Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2019) Assessment of Computed Tomography (CT) And Magnetic Resonance Imaging (MRI) Based Radiosurgery Treatment Planning for Pituitary Adenomas. Canc Therapy & Oncol Int J 13: 555857.
- Demiral S, Sager O, Dincoglan F, Uysal B, Gamsiz H, et al. (2018) Evaluation of Target Volume Determination for Single Session Stereotactic Radiosurgery (SRS) of Brain Metastases. Canc Therapy & Oncol Int J 12: 555848.
- Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2022) Optimal timing of thoracic irradiation for limited stage small cell lung cancer: Current evidence and future prospects. World J Clin Oncol 13(2): 116-124.
- Demiral S, Sager O, Dincoglan F, Uysal B, Gamsiz H, et al. (2021) Evaluation of breathing-adapted radiation therapy for right-sided early stage breast cancer patients. Indian J Cancer 58(2): 195-200.
- Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2021) Concise review of stereotactic irradiation for pediatric glial neoplasms: Current concepts and future directions. World J Methodol 11(3): 61-74.
- Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2021) Omission of Radiation Therapy (RT) for Metaplastic Breast Cancer (MBC): A Review Article. International Journal of Research Studies in Medical and Health Sciences 6(1): 10-15.
- Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2020) Adaptive radiation therapy of breast cancer by repeated imaging during irradiation. World J Radiol 12(5): 68-75.
- Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2019) Breathing adapted radiation therapy for leukemia relapse in the breast: A case report. World J Clin Oncol 10(11): 369-374.
- Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2019) Utility of Molecular Imaging with 2-Deoxy-2-[Fluorine-18] Fluoro-DGlucose Positron Emission Tomography (18F-FDG PET) for Small Cell Lung Cancer (SCLC): A Radiation Oncology Perspective. Curr Radiopharm 12(1): 4-10.
- Sager O, Dincoglan F, Uysal B, Demiral S, Gamsiz H, et al. (2018) Evaluation of adaptive radiotherapy (ART) by use of replanning the tumor bed boost with repeated computed tomography (CT) simulation after whole breast irradiation (WBI) for breast cancer patients having clinically evident seroma. Jpn J Radiol 36(6): 401-406.
- Sager O, Dincoglan F, Uysal B, Demiral S, Gamsiz H, et al. (2017) Splenic Irradiation: A Concise Review of the Literature. J App Hem Bl Tran 1: 101.
- Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Uysal B, et al. (2015) Adaptive splenic radiotherapy for symptomatic splenomegaly management in myeloproliferative disorders. Tumori 101(1): 84-90.
- Ozsavas EE, Telatar Z, Dirican B, Sager O, Beyzadeoglu M (2014) Automatic segmentation of anatomical structures from CT scans of thorax for RTP. Comput Math Methods Med 2014: 472890.
- Dincoglan F, Beyzadeoglu M, Sager O, Oysul K, Kahya YE, et al. (2013) Dosimetric evaluation of critical organs at risk in mastectomized left-sided breast cancer radiotherapy using breath-hold technique. Tumori 99(1): 76-82.
- Sager O, Dincoglan F, Gamsiz H, Demiral S, Uysal B, et al. (2012) Evaluation of the impact of integrated [18f]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography imaging on staging and radiotherapy treatment volume definition of nonsmall cell lung cancer. Gulhane Med J 54: 220-227.
- Sager O, Beyzadeoglu M, Dincoglan F, Oysul K, Kahya YE, et al. (2012) The Role of Active Breathing Control-Moderate Deep Inspiration Breath-Hold (ABC-mDIBH) Usage in non-Mastectomized Left-sided Breast Cancer Radiotherapy: A Dosimetric Evaluation. UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi 22: 147-155.
- Sager O, Beyzadeoglu M, Dincoglan F, Oysul K, Kahya YE, et al. (2012) Evaluation of active breathing control-moderate deep inspiration breath-hold in definitive non-small cell lung cancer radiotherapy. Neoplasma 59(3): 333-340.
- Beyzadeoglu M, Sager O, Dincoglan F, Demiral S, Uysal B, et al. (2020) Single Fraction Stereotactic Radiosurgery (SRS) versus Fractionated Stereotactic Radiotherapy (FSRT) for Vestibular Schwannoma (VS). J Surg Surgical Res 6: 062-066.
- Dincoglan F, Beyzadeoglu M, Sager O, Demiral S, Uysal B, et al. (2020) A Concise Review of Irradiation for Temporal Bone Chemodectomas (TBC). Arch Otolaryngol Rhinol 6: 016-020.
- Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Gamsiz H, et al. (2020) Multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation: Implications for an improved toxicity profile. J Surg Surgical Res 6: 056-061.
- Dincoglan F, Sager O, Uysal B, Demiral S, Gamsiz H, et al. (2019) Evaluation of hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity after surgical resection of brain metastases: A single center experience. Indian J Cancer 56(3): 202-206.
- Demiral S, Dincoglan F, Sager O, Uysal B, Gamsiz H, et al. (2018) Contemporary Management of Meningiomas with Radiosurgery. Int J Radiol Imaging Technol 80: 187-190.
- Dincoglan F, Sager O, Demiral S, Uysal B, Gamsiz H, et al. (2017) Radiosurgery for recurrent glioblastoma: A review article. Neurol Disord Therap 1: 1-5.
- Dincoglan F, Sager O, Demiral S, Gamsiz H, Uysal B, et al. (2019) Fractionated stereotactic radiosurgery for locally recurrent brain metastases after failed stereotactic radiosurgery. Indian J Cancer 56(2): 151-156.
- Gamsiz H, Beyzadeoglu M, Sager O, Demiral S, Dincoglan F, et al. (2015) Evaluation of stereotactic body radiation therapy in the management of adrenal metastases from non-small cell lung cancer. Tumori 101: 98-103.
- Dincoglan F, Beyzadeoglu M, Sager O, Demiral S, Gamsiz H, et al. (2015) Management of patients with recurrent glioblastoma using hypofractionated stereotactic radiotherapy. Tumori 101(2): 179-184.
- Demiral S, Dincoglan F, Sager O, Gamsiz H, Uysal B, et al. (2016) Hypofractionated stereotactic radiotherapy (HFSRT) for who grade I anterior clinoid meningiomas (ACM). Jpn J Radiol 34(11): 730-737.
- Sager O, Dincoglan F, Beyzadeoglu M (2015) Stereotactic radiosurgery of glomus jugulare tumors: Current concepts, recent advances and future perspectives. CNS Oncol 4(2): 105-114.
- Gamsiz H, Beyzadeoglu M, Sager O, Dincoglan F, Demiral S, et al. (2014) Management of pulmonary oligometastases by stereotactic body radiotherapy. Tumori 100(2): 179-183.
- Sager O, Beyzadeoglu M, Dincoglan F, Gamsiz H, Demiral S, et al. (2014) Evaluation of linear accelerator-based stereotactic radiosurgery in the management of glomus jugulare tumors. Tumori 100(2): 184-188.
- Demiral S, Beyzadeoglu M, Sager O, Dincoglan F, Gamsiz H, et al. (2014) Evaluation of linear accelerator (linac)-based stereotactic radiosurgery (srs) for the treatment of craniopharyngiomas. UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi 24: 123-129.
- Demiral S, Beyzadeoglu M, Sager O, Dincoglan F, Gamsiz H, et al. (2014) Evaluation of Linear Accelerator (Linac)-Based Stereotactic Radiosurgery (Srs) for the Treatment of Craniopharyngiomas. UHOD-Uluslararasi Hematoloji Onkoloji Dergisi 24(2): 123-129.
- Sager O, Beyzadeoglu M, Dincoglan F, Uysal B, Gamsiz H, et al. (2014) Evaluation of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) for cerebral cavernous malformations: A 15-year single-center experience. Ann Saudi Med 34(1): 54-58.
- Dincoglan F, Sager O, Gamsiz H, Uysal B, Demiral S, et al. (2014) Management of patients with ≥ 4 brain metastases using stereotactic radiosurgery boost after whole brain irradiation. Tumori 100(3): 302-306.
- Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Uysal B, et al. (2013) Management of vestibular schwannomas with linear accelerator-based stereotactic radiosurgery: a single center experience. Tumori 99(5): 617-622.
- Dincoglan F, Beyzadeoglu M, Sager O, Uysal B, Demiral S, et al. (2013) Evaluation of linear accelerator-based stereotactic radiosurgery in the management of meningiomas: A single center experience. J BUON 18(3): 717-722.
- Demiral S, Beyzadeoglu M, Uysal B, Oysul K, Kahya YE, et al. (2013) Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer. Neoplasma 60(3): 322-327.
- Dincoglan F, Beyzadeoglu M, Sager O, Oysul K, Sirin S et al. (2012) Image-guided positioning in intracranial non-invasive stereotactic radiosurgery for the treatment of brain metastasis. Tumori 98(5): 630-635.
- Dincoglan F, Sager O, Gamsiz H, Uysal B, Demiral S, et al. (2012) Stereotactic radiosurgery for intracranial tumors: A single center experience. Gulhane Med J 54: 190-198.
- Sirin S, Oysul K, Surenkok S, Sager O, Dincoglan F, et al. (2011) Linear accelerator-based stereotactic radiosurgery in recurrent glioblastoma: A single center experience. Vojnosanit Pregl 68(11): 961-966.